Since its development in the 1990s, Phenolic Impregnated Carbon Ablator (PICA) has been the state-of-the-art material for light-weight ablative thermal protection systems (TPS). PICA was developed by NASA and served as the heat shield material for the Stardust sample return capsule and Mars Science Laboratory. However, PICA has some disadvantages such as brittleness, low char yield, low decomposition onset temperature, and low glass transition temperature.
Recent research has investigated flexible and conformal pyrolyzing ablators. One product of this research was Conformal Phenolic Impregnated Carbon Ablator (CPICA), which uses a carbon felt substrate with a phenolic polymer matrix similar to that of PICA.
Although phenolic resin has an extensive history in high- and low-density TPS materials, it would be an advance in the art to develop alternative resins that offer advantages such as higher char yield, higher char strength, higher decomposition onset temperature, and increased glass transition temperature as compared to state-of-the-art phenolic. It would be advantageous to develop new classes of TPS materials that generate no volatiles during curing, are low in density, and have a polymer morphology similar that of phenolic in PICA.